VS: VS: Dealing with the limitation of only positive neural signals

[Eetu Pikkarainen 2017-08-17]

Fred,

I found really difficult to interpret my diagram into your example. Perhaps it is possible, but perhaps the example is too complicated and requires a hierarchical setting
of control loops.

A simpler case is easier: push an object to a certain point in a line. If the object is not yet there then the perception is lower than the reference and the first comparator
produces an error which goes to the “positive” output function and you push more. The other comparator produces zero error. If the object goes further from the target point then the perception is higher than the reference and then the first comparator produces
zero – you do not push more. The other comparator produces an error to the “negative” output function and you start to draw the object back.

This same should apply to keeping the car in the center of the lane, but the symmetry of the situation makes us think that two (or more) control loops are needed.

image001118.png

···

Eetu

Please, regard all my statements as questions,

no matter how they are formulated.

Lähett****äjä: Fred Nickols [mailto:fred@nickols.us]
Lähetetty: 16. elokuutata 2017 19:09
Vastaanottaja: csgnet@lists.illinois.edu
Aihe: RE: VS: Dealing with the limitation of only positive neural signals

[From Fred Nickols (2017.08.16.1207)]

I knew I was getting in over my head. That said, how does the arrangement below serve to keep the car in the center of the lane.

I especially don’t get how r-p and p-r fit in.

Walk me through it, please.

Fred Nickols

From: Martin Taylor [mailto:mmt-csg@mmtaylor.net]
Sent: Wednesday, August 16, 2017 9:37 AM
To: csgnet@lists.illinois.edu
Subject: Re: VS: Dealing with the limitation of only positive neural signals

[Martin Taylor 2017.08.16.09.35]

On 2017/08/16 3:21 AM, Eetu Pikkarainen wrote:

Martin,

did you men something like this:

Yes. Thanks for drawing the picture.

Martin

Eetu

Please, regard all my statements as questions,

no matter how they are formulated.

-----Alkuperäinen viesti-----
Lähettäjä: Martin Taylor [mailto:mmt-csg@mmtaylor.net]

Lähetetty: 16. elokuutata 2017 8:13
Vastaanottaja: csgnet@lists.illinois.edu
Aihe: Re: Dealing with the limitation of only positive neural signals

[Martin Taylor 2017.08.16.01.06]

[From Fred Nickols (2017.08.15.1537 ET)]

Martin:

The attached .jpg diagram illustrates what I was talking about when I

referred to having different (yet connected) control systems for the

right and left positions of the car in its lane. That was my way of

getting around situations Rick raised where r might larger than p or p

might be larger than r, suggesting a negative or positive error yet

only positive neural signals are known to exist. Does it fit with the way you see it?

Not quite. I would have only one perceiving function and one reference value signal. Those signals would be sent to two comparators, one of which would have zero output if the error were rightward and the other would
have zero output if the error were leftward. Otherwise, I think the rest of it more or less coincides with my view. The perceiver doesn’t have to have zero output for the car being in the middle of its lane, so you don’t need separate ones for left of centre
and right of centre.

Martin